Coupling for tubes and pipes



fFeb. 6, 194 0. H K|E|DEL 2,189,566

COUPLING FOR TUBES AND PIPES Filed July 13, 1938 2 Sheets-Sheet l lNVENTOR 152 11.; ffralizl ATTORNEYS Feb. 6, 1940. H. KREIDEL 2,139,566

COUPLING FOR TUBES Aub urns Filed July 13, 1938 2 Sheets-Sheet 2 1V \NVENTOR 2:011.) Zia [El W I K W ATTORNEYS Patented Feb. 6, 1940 UNITED STATES PATENT OFFICE 2,189,566 COUPLING FOR TUBES AND PIPES Hans Kreidel, Wiesbaden, Germany, assignor to Patex Societe Anonyme, Basel, Switzerland, a corporation of Switzerland Application July 13, 1938, Serial No. 218,901 In Germany December 30, 1937 3 Claims. (Cl. 285-122) This invention relates to couplings for rigid or stresses or vibrations to which the pipe may be flexible pipes, and more particularly to couplings subjected do not cause the end of the pipe to of the kind in which the inner surface of the come away from its seating, and also to prevent end of the pipe, after having been flared conically the pipe from rotating when the coupling mem- 5 or flanged perpendicularly to form a rim, is bars are tightened. Finally, when the material 5 pressed by means of two coupling members which of the pipe is forced into the hollows or cavities. are adapted to be coupled together against a the force applied in tightening the coupling need conical seating or a seating which is perpendicnot be so great as to lengthen, and therefore reular to the axis of the pipe and which may be duce the thickness of the end of the tube to any formed either on one of the coupling members or considerable extent, both of which are factors 10 on a separate inserted piece. which tend to produce rupture. In addition, the

In the known connections of this kind the coupling can be assembled and disconnected as seating. against which the conically flared or require While absolute tightness is ensured flanged end of the pipe bears is smooth. This when the coupling is re-connected.

has the following disadvantages: When the nut In accordance with a further feature of the 15 is tightened, the pipe may be rotated with the invention, the cavities or hollows provided in the nut since the flared or flanged end of the pipe seating against which the end' of the pipe is can slide on the smooth surface of its seating, pressed are arranged in the form of a checkerwhich has no means for preventing this. board or grid-like design.

When it is desired to join pipes made of a com- Preferably, the cavi are square and become paratively soft material such as tempered copnarrower towards the bottom and are so arranged per, for example, the tightening stress often flatthat two opposite sides are parallel or substantens the flared or flanged end of the pipe against tially parallel to the axis of the pipe to be conthe smooth seating and thereby reduces its nected, whereby the dismantling and re-assembly 5 mechanical strength. are facilitated.

Since the end of the pipe is maintained against In one preferred form of coupling, in accordthe smooth seating solely by the pressure exance with the invention, the seating against erted by the coupling members, it will readily be which the pipe is pressed consists of a conical or realized that the pressure of the confined fluid, bi-conical ring, the outside surface of which is 0 or the effect of the tensile stresses or vibrations provided with cavities arranged in checkerboard to which the pipe may be subjected, can easily or grid-like formation as described above. cause the end of the pipe to become detached According to another form, a collar which is from its seating, while if the tensile stress is flanged on the end of the pipe, is pressed against sufficiently great, the end of the pipe may even a gasket, the outside surface of which is provided be entirely broken off. with similar cavities. 35

The joint formed by pressing the conically In order that the invention may be readily flared mouth or the flanged end of the pipe understood and carried into effect, various forms against a smooth seating is often unreliable from of pipe couplings in accordance with the inventhe point of view of tightness, in particular when tion are illustrated by way of example in the 40 the thickness of the end of the pipe is not uniaccompanying drawings, in which 40 form or if its uniformity is not maintained when Figure 1 shows a section through one form of the coupling members are tightened. pipe coupling according to this present inven-- The object of the present invention is to protion, before the parts are coupled together; vide an improved pipe connection by which the Fig. 2 shows a similar section, after the parts above mentioned disadvantages are obviated. have been screwed up; 45

According to the invention, the seating against Fig. 3 is a detail view of parts of Fig. 2 on a which the flared or flanged end of the pipe is larger scale; I

pressed is provided with small hollows or cavities, Fig. 4 shows a section throu o her fo m which are closed at the bottom and are of any f pipe p i n which the n of the p p s so desired shape, the effect of which is that, when p ss d a ai st a ri p v d d wit avities arthe coupling is tightened, the material of the a ed in c e b formation;

pipe is partly forced into the small cavities or Fig. 5 shows the ring of Fig. 4 on a larger hollows, so thatthe end of the pipe becomes scale;

anchored to its seating. The purpose of this Fig. 6 is a section through another form of is to ensure a perfectly tight joint, so that tensile coupling in which the end of the pipe is pressed against a separate inserted ring by means of two coupling members which are in the form of rings or flanges;

Fig. 7 is a section of a coupling in which a collar, which is flanged on the end of the pipe to be connected, is pressed against a gasket;

Fig. 8 shows, on a larger scale, the gasket employed in Fig. '7; and

Figs. 9 and 10 are sections showing two further forms of couplings according to the present invention.

Referring to Figs. 1', 2 and 3, a designates the pipe to be connected, the end of which has been flanged and more particularly flared conically, preferably in such a way as to avoid the formation of a sharp angle. The reference b indicates one of the coupling members having an external screw thread 0 on which a second coupling member in the form of a nut d can be screwed.

The inner surface d1 of the nut is of the same taper as the flared mouth of the pipe a. The nut d must either be placed on the pipe a before the mouth has been flared, or, if this has already been done, the nut may be introduced over the other end of the pipe.

The coupling member b has a conical seating In for receiving the flared end of the pipe a, with which it must form a tight joint. The taper of this seating is the same as that of the surface d1 of the nut d. The seating in on the coupling member b has closed hollows or cavities b2. The cavities in are preferably arranged in checkerboard or grid-like fashion, and become smaller towards the bottom. The walls of the cavities, against which the inner surface of the pipe to be connected is pressed, may be either parallel or substantially parallel to the axis of the pipe, or they may be at an angle thereto,

As will be seen, more particularly in Fig. 3, one of the walls of each of the cavities be is parallel to the axis of the pipe, which has the advantage of permitting easy removal and re-connection of the pipe, because, when the cavities are of the form illustrated, the pipe a can be separated from its seat In by withdrawing it axially, without the material which has been forced into the cavities in being able to hinder this operation. If the cavities b2 were of a different shape, there would be a possibility that the material forced into the cavities might hinder the subsequent disconnection of the pipe.

In an exceptional case when it is desired to assemble the tube permanently so that any subsequent disconnection becomes impossible, it is preferable to slope one of the walls of the cavities in such a manner that the material which is forced into the cavities connection is tightened preventing withdrawal of the pipe when an axial pull is exerted on it.

The checkerboard or grid-like pattern of the cavities into which some of the material of the pipe is forced when the connection is tightened has the advantage that the cavities in the seating do not inter-communicate, so that all leakage, even that due to capillary action is practically impossible. With the grid-like pattern for the cell-like cavities there will be a multiplicity of cavities spaced from each other and arranged in a plurality of concentric rows. The outer surface of the partitions between the cavities and the outer surface of the seating portion to the sides of the rows of cavities is smooth. Each cavity is preferably substantially square or rectangular at the top.

A On the other hand, since the pipe does not rotate with the nut on disconnection, its inner surface is not injured, and the joint can be reconnected with the same tightness as on the first assembly.

Since the pipe is flrmly anchored to its seating, vibrations, torsional or tensile stresses exerted on the pipe cannot affect the tightness of the joint.

The pipe coupling of the present invention is mainly applicable to pipes made of material such that the end of the pipe can be flanged as by flaring without difllculty, for example, copper, lead, aluminum or light alloys, possibly also steel tubes. or for rubber pipes, or pipes of any other plastic or elastic material.

Fig. 4 shows the connection of two pipes-e and er the ends of which are conically flared. Instead of being pressed against a conical seating on one of the coupling members, as described in connection with Figs. 1 to 3, the ends of the pipes e and er are pressed against a bi-conical ring which is illustrated in detail in Fig. 5. The internal diameter ii of the ring f is preferably equal to the internal diameter of the pipe to be connected. Its conical surfaces f2 and f: are provided with cavities be disposed in a checkerboard pattern. This ring can be provided with a conical grove f4.

This form of pipe connection is assembled in the following manner: A coupling member 9 provided at one end with a male screw thread or has a conical seating surface a: the taper of which corresponds to that of the surfaces f2 and f: of the ring I. A second coupling member or nut H having a female screw thread H1 engages the male thread 91 of the coupling member g. The nut H may have a conical seating surface of a taper corresponding to that of the surfaces f2 and is of the ring f in the same way as the nut d in Fig. 1. Instead of forming the nut with a conical seating, there can also be placed in the bottom a separate part I having a conical surface I1, the taper of which corresponds to that of the surfaces is and f: of the ring I can be inserted in the nut as shown in Fig. 4.

When the coupling members g and H are tightened, the conical surface 92 of the member 9 on the one hand and the conical surface I1 of the part I on the other hand, force the material of the pipe into the cavities be on the surfaces is and fa of the bi-conical ring I. All the advantages of the connection shown in Figs. 1 to 3 are thus obtained for this form also.

Fig. 6 shows a pipe connection similar to that shown in Fig. 4, the only difference being that rings or flanges K and K1 which are connected by means of bolts K2 and nuts K; are used for tightening. The rings or flanges K and K1 have conical surfaces K4 and K5, the taper of which corresponds to the taper of the surfaces of the bi-conical ring Ks, which is identical with the ring j which is illustrated in Fig. 5.

Fig. '7 shows a pipe connection similar to that shown in Fig. 4. In this form of connection, the ends of the pipe, instead of being conically flared, are flanged so as to form rims L and L1 which are perpendicular or substantially perpendicular to the axis of the pipes to be joined. The flanged rims L and L1 are tightened by means of the coupling members L2 and In with a flat end against a gasket L4 having a sunk checkerboard design 132, as previously described, and as can be seen in Fig. 8.

Instead of pressing the flanged rim L or Li against a gasket L4 provided with cavities b2, the rim can be pressed, as in Figs. 1 to 3, directly against a seating on one of the coupling members,

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the seating in this case being perpendicular instead of conical.

Fig. 9 shows a coupling member M which is screwed into a cast port and of which the conical seating In is provided with cavities arranged in a checkerboard pattern, the pipe being gripped be tween the coupling members in the manner described with reference to Figs. 1 to 3.

In Fig. 10 the coupling member N is identical with the member M shown in Fig. 9, but the end of the pipe is pressed against a bi-conical ring F the surfaces of which are provided with cavities arranged in checkerboard pattern, as described in connection with Figs. 4 and 5. In this case, one of the conical surfaces fits tightly into a conical bore N1 of the member N.

The various forms of coupling which have been described by way of example, all have in common the characteristic feature that the seating for the inner surface of the pim is provided with cavities, which are preferably arranged in the manner specified. The coupling can be used for joining tubes or pipes to faucets or taps or any other plumbing fittings, such as T-pieces, X-pieces, angle pieces, etc.

What I claim is:

1. In a coupling for a pipe having a flanged end, a member providing a seat for sealing engagement with said flanged end, said member containing a plurality of individual blind recesses spaced from one another and from the ends of said member, each of said recesses being surrounded by a substantially smooth area defined by said seat, and means for urging said pipe and member into sealing relationship.

2. In a coupling for a pipe having a flanged end,

a member providing a seat for sealing engagement with said flanged end, said member containing a plurality of individual blind recesses spaced from one another and from the ends of said mem: ber, each recess having a wall substantially parallel to the axis of said member, each of said recesses being surrounded by a substantially smooth area defined by said seat, and means for urging said pipe and member into sealing relationship.

3. In a coupling for a pipe having a flanged end,

a member providing a seat for sealing engagement with said flanged end, said member containing a plurality of substantially concentric rows of individual blind recesses spaced from one another and from the ends of said member, each of said recesses being surrounded by a substantially smooth area defined by said seat, and means for urging said pipe and member into sealing rela tionship.

HANS EL. 

